During extended ground maintenance times, various protective devices are commonly installed to prevent damage to instrumentation and/or structural damage to the aircraft. Representative are pitot tube covers and landing gear locks pins.
Pitot tubes are used on aircraft for measuring speed and altitude. They are sensitive and delicate, and thus prone to damage during maintenance, and storage. To limit damage and contamination, the pitot tube covers are installed during any appreciable outdoor layover to prevent dust, particulates, water, and other foreign matter from entering the probe ports, all of which can contribute to erroneous outputs. Equally important to installation during layover is the need to remove the pitot tube covers prior to flight. Should they remain in place during flight, there are no effective procedures for removal and the instrument's assessment of speed and altitude are severely compromised. Accordingly and, as a matter of standard operating procedure, if not removed the plane must return to base for cover removal. Inasmuch as the plane may have departed with a full fuel load, landing under such high loading conditions can create substantial forces that can damage the airframe or otherwise affect structural integrity. It would therefor be desirable to provide an apparatus and procedure for assuring the removal of pitot covers prior to flight.
It is also desirable to provide the pitot covers and installation equipment in a package that can be carried on the associated plane, thus enabling aircraft, such as military, commercial or business planes, that are transient between facilities of varying ground maintenance capabilities, to have assured access to the covers regardless of landing location. It is also desirable to limit the number of separate items on any maintenance package. Thus installation equipment such as installation poles for higher mounted pitot tubes may be necessary and unavailable at remote locations but present an additional piece of equipment that must. It would thus be further desirable to integrate installation equipment in an assembly that could be readily stowed on and transported with the aircraft. On many aircraft, the covers may be manually installed without auxiliary equipment. On other aircraft, the probes are just out of reach and require installation tools. For larger aircraft with higher mounted probes, an installation tool such as disclosed in our pending application, U.S. Ser. No. 12/580,234 filed on Oct. 15, 2009, provides effective installation assistance. The tool, however, is considered too bulky for aircraft transport, and is generally conveniently available at facilities able to handle the larger aircraft.
The landing gear lock pins are installed to disable the landing gear retracting system to prevent inadvertent actuation during maintenance and/or ground operations that could collapse the nose wheel and structurally damage the aircraft. As with the pitot tube covers, the pins must be removed prior to flight, and if not removed, the plane must return to base with the resultant unnecessary expense and potential structural damage from a ful weight landing.
While there are established procedures for removing the covers and lock pins, human error nonetheless continues to produce non-compliant flights. Accordingly, it would be desirable to provide a maintenance product that would further reduce the chances of the covers and lock pins remaining on the aircraft at takeoff.